[单选题]
The reason the position of a particlz ux1keq5nwfl.61q ,ye cannot beoyqs :du(2pv+l d3ffr +z) i2k specified with infinite precision is the fu2zd(dip2qk++r ls: 3yf vo)
A. exclusion principle.
B. uncertainty principle.
C. photoelectric effect.
D. principle of relativity.
